Exoplanetary atmospheres

The characterization of exoplanetary atmospheres is one of the hottest topics in astrophysics nowadays.

Retrieving information about the chemical composition and the structure of the layers of gas surrounding far-away planets can help us understand how they formed and how they will evolve. The most used technique to study the atmospheres of alien worlds is the transmission spectroscopy which is based on the analysis of the starlight filtered by the chemical species in the atmosphere. This can be performed by ground-based spectrographs, such as HARPS-N, or via instruments on board space missions, like JWST or Ariel in the next few years.

In order to interpret observations we need theoretical models to compare with observed data. For  this purpose it  is possible to develop  numerical models that, assuming the radiative-convective equilibrium, calculate vertical pressure temperature profiles as a function of the stellar energetic input and the atmospheric chemical abundance.  Furthermore it is possible to develop chemical codes that, taking into account equilibrium and disequilibrium processes, calculate chemical abundances for the most important atomic, ionic and molecular species present in the atmosphere for a variety of astrophysical environments. Thanks to the temperature and chemical profiles it is possible to calculate synthetic spectra that, if compared with observed spectra, allow retrieval of the temperature and the chemical abundances of exoplanetary atmospheres. Our research group developed expertise in this field that runs from the data analysis techniques  to numerical models developments.

“Absorption tomography of H-alpha in Kelt 9b. It is obtained by dividing the in-transit spectra of each night (ordered by phase) by its own master-out. The result is a visual representation of the planet’s atmosphere absorption and in this specific case H-alpha. The dark trace represents the Halpha absorption present in the planet’s atmosphere. The signal follows the expected radial velocity curve, represented in red. The brightest region is due to the Rossiter-McLaughlin effect caused by the transit geometry. The two white lines represent the beginning and end phases of the transit.

Team

Laura Affer
Researcher
Email: laura.affer @inaf.it
ORCID: 0000-0001-5600-3778 		 Mattia Claudio D’Arpa
PhD Student
Email: mattia.darpa @inaf.it
ORCID:  
Claudia Di Maio
Researcher
Email: claudia.dimaio @inaf.it
ORCID: 0000-0002-8669-1150 		 Daniele Locci
Researcher
Email: daniele.locci @inaf.it
ORCID: 0000-0002-9824-2336 
Antonio Maggio
Researcher
Email: antonio.maggio @inaf.it
ORCID: 0000-0001-5154-6108 		 Giusi Micela
Head of ExoPa
Email: giusi.micela @inaf.it
ORCID: 0000-0002-9900-4751 
Antonino Petralia
Researcher
Email: antonino.petralia @inaf.it
ORCID: 0000-0002-9882-1020 		 Cesare Cecchi Pestellini
Researcher
Email: cesare.cecchipestellini @inaf.it
ORCID: 0000-0001-7480-0324 

Students